Instant noodles are made through the steps in which raw noodle lines obtained by cutting are gelatinized and then dried by a drying method such as fry drying, hot-air drying or freeze drying. Instant noodles can be easily eaten only by cooking in which instant noodles are soaked with hot water and then left for about 3 to 5 minutes, or are boiled for about 1 to 3 minutes. Accordingly, instant noodles are an extremely convenient instant food. It is important factor for instant noodles to fully reconstitute a lush texture within the aforementioned predetermined cooking time. However, when noodle lines are thick, sufficient texture is not reconstituted only by soaking instant noodles with hot water and then leaving it for about 3 to 5 minutes, and non-reconstituted center lines can remain in thick noodle lines. In recent years, the demand for instant noodles made of thick noodle lines has particularly grown due to the diversification of consumers' needs, and a method for improving the reconstitution property has become a very useful technique in the field of instant noodles.
The technique to improve the reconstitution property of instant noodles has been already developed, and examples thereof include the method using salt. Patent Literature 1 discloses the manufacturing method of noodles with a quick reconstitution property in which noodles are boiled with salt-free water and then boiled with brine having a certain salt content, and the noodles with a quick reconstitution property obtained by the manufacturing method thereof. Patent Literature 2 discloses the manufacturing method of instant dried noodles in which noodle sheets or noodle lines made by a conventional method are soaked in the brine at a high temperature of 60° C. to 130° C. and then dried. Patent Literature 3 discloses the instant noodles manufactured through the steps in which noodle lines are boiled with a solution having a high salt content and then washed with water. Patent Literature 4 discloses the manufacturing method of instant noodles characterized in that raw noodle lines are steamed, soaked and boiled in a salted aqueous solution or a salt-containing aqueous emulsion, subjected to liquid removal, preliminarily dried at a temperature of 40° C. to 100° C., and then mainly dried at a temperature of 110° C. to 200° C.